Plastic paint



Patented Dec. 11, 1934 PLASTIC PAINT Dean De Forest C to National Gypsum randell, Buffalo, N. Y., assignor Company, Buflalo, N. Y., a

corporation of Delaware No Drawing. Ap

Serial No.

4 Claims.

This invention relates to a plastic or cold water paint in which glue is used as a binder and which is sold to the trade in the form of a surfaces in relatively thick layers.

The primary object of the invention is to give an inexpensive, very finely rough-textured surface to paint of this character. objects of the invention Other minor and practical solutions thereof are disclosed in detail in the herein patent specification.

My invention may be embodied in various paint compositions or formulas, and the present disclosure is therefore to be regarded one commercially successful factorily carries out the invention in Any paint or other merely as plastic which satispractice.

surface coating which, when dry, is perfectly smooth and flat, has the objection that fingermarks on or minor blemishes in the surface thereof are glaringly evident and conspicuous.

Also in most cases such a smooth surface does not harmonize with the furniture and other fittings in the room. For

paint which will it is usually desirable to have a this reason provide .a very finely rough-textured surface rather than an absolutely smooth finish or the invenprincipally relatively coarsely crushed and flaky clam shells. The natural structure of clam shells is laminated, and clam shells is utilized in by only using clam shells which this characteristic of the present invention have been coarsely crushed to form flakes or irregular disks rather than ground to form a fine,

powder. By the use of such flake-er forms a constituent,

shells, the paint, of which it amorphous ushed clam is provided on its surface when dry with a very large which are relatively strong by reason that the grain of each flake lies the plane of each clam shell flake.

number of fine but sharp prongs or points of the fact parallel to The size of the flake-crushed clam shells which have been successfully used for this purpose in plastic paint is as follows:

Retained on 20 mesh screen trace Retained on 40 mesh screen trace Retained on mesh screen not over 45% Retained on 200 mesh screen 25-35% Through 200 mesh screen 20-30% plication January 31, 1931,

In plastic paints, (as is well known in the art) the binder is usually a dry'and finely-pulverized glue such as casein. The rest of the ingredients of the paint, in the form in which it is sold to be consumed, are also dry and are either ground, pulverized or otherwise comminuted, the complete mixture forming a dry powder which is adapted to be mixed on the job with a suitable proportion of water. This water dissolves or forms an emulsion with the casein or other glue binder in the paint so that when said paint is spread upon walls or other surfaces in relatively thick layers, said casein dries out and becomes hard and solid through the process of evaporation and thereby causes itself and all of the other constituents in the paint to firmly adhere to said walls.

Such a drying process is not to be confused with liquid paints and other coatings which are sold to the customer in the form of a liquid emulsion containing linseed oil or some other similar vehicle. Such a liquid coating having a vehicle is adapted to be applied to walls or other surfaces in relatively thin coats with a paint brush and is later caused to harden by the oxidation of said vehicle, whereas in plastic paints the substance which holds the paint together and causes it to adhere to the wall is a glue such as casein which is necessarily more viscous and must be put on the walls in relatively thick coats, and is caused to dry out by the process of evaporation rather than that of oxidation.

A composition of plastic paint which has given very satisfactory service is constituted as follows (in terms of parts by weight) By using clam shells which are crushed to form flakes, not only is the paint given a finely roughtextured surface but it is also given a scintillating quality due to the reflection of light from the flat, and therefore more or less reflecting faces or facets of each clam shell flake. If these clam shells were pulverized instead of being flakecrushed the result would be an amorphous or approximately round. grained powder which would not have any facets to reflect light waves and would therefore not cause the surface of the plastic paint to scintillate as in the present invention.

It is obvious that other mollusk shells may be used instead of clam shells,in fact any substance is satisfactory to a greater or less degree which is of a laminated nature so as, when crushed, to result in the formation of flakes. It is, of course, preferable to use a material which has a relatively high tensile strength and which also is provided with facets that reflect a considerable portion of the light waves impinging thereon. It is also desirable to use a material whose cost is low. Flake mica is a very excellent material for this purpose, especially as to its scintillating properties, for which reason a certain portion of mica has been included in the formula for plastic paint given herein. The cost of mica is, however, very high, whereas crushed clam shells have to a very high degree the qualities of fiakiness, strength and scintillation and at the same time are very inexpensive and are therefore indicated in the formula as constituting a greater component percentage than the component percentage of the mica. Other mollusk shells such as flake-crushed oyster shells, etc. may, of course, be employed in the manufacture of plastic and other paints but in most cases the qualities desired are found to a higher degree in flakecrushed clam shells and the latter have proven a Lia: l; 1

very satisfactory paint ingredient in commercial practice.

I claim as my invention:

1. A texture paint comprising crushed mollusk shells substantially all of which pass through a mesh screen and not more than 30% of which pass through a 200 mesh screen, the quantity of said crushed shells to the total quantity of paint so modifying the characteristics of said paint as to enable the same to be spread upon a surface to give a relatively rough textured surface.

2. A texture paint comprising crushed mollusk shells substantially all of which pass through a 40 mesh screen and 20 to 30% of which are retained on a 200 mesh screen, the quantity of said crushed shells to the total quantity of paint so modifying the characteristics of said paint as to enable the same to be spread upon a surface to give a relatively rough textured surface.

3. A texture paint comprising a binder and crushed mollusk shells in flake form, not more than 30% of which pass through a 200 mesh screen, the quantity ofsaid crushed shells being 20 to 30% of the total constituents of the paint exclusive of coloring matter.

4. A texture paint comprising a binder and crushed mollusk shells in flake form, substantially all of which pass through a 40 mesh screen and not more than 30% of which pass through a 200 mesh screen, the quantity of said crushed shells being 20 to 30% of the total constituents of the paint exclusive of coloring matter DEAN DE FOREST CRANDELL. 

